The weather in Seattle now is great. In the past say 3 weeks, it’s only rained once, on the morning of a weekday. The rest of the time it’s been sunny and the sky has been clear. Now normally that would mean that you would be burning in the heat, and while the sun does heat you up quite a bit, all it does is raise the ambient temperature from say 18°C to 25°C. So it’s warm enough that you won’t need a coat but not that hot either. The hottest day so far has been yesterday (last night around sunset to be exact) and it was a sweltering 29°C with no humidity.
As the saying goes, it’s not the heat that gets ya, it’s the humidity.